Welding electrode cutting tool and method of using the same

Abstract

A cutting tool that can simultaneously cut and restore asymmetric weld face geometries of two welding electrodes that are subject to different degradation mechanisms is disclosed along with a method of using such a cutting tool during resistance spot welding of workpiece stack-ups that include dissimilar metal workpieces. The cutting tool includes a first cutting socket and a second cutting socket. The first cutting socket is defined by one or more first shearing surfaces and the second cutting is defined by one or more second shearing surfaces. The first shearing surface(s) and the second shearing surface(s) are profiled to cut and restore a first weld face geometry and a second weld face geometry, respectively, that are different from each other upon receipt of electrode weld faces within the cutting sockets and rotation of the cutting tool.

The invention claimed is: 
     
       1. A cutting tool capable of dressing a weld face of a first welding electrode so that the weld face of the first welding electrode has a first weld face geometry, and dressing a weld face of a second welding electrode so that the weld face of the second welding electrode has a second weld face geometry, in which the first weld face geometry and the second weld face geometry are different from each other, the cutting tool comprising:
 a body having a first end and a second end that are spaced apart along a central axis of the body, the first end of the body having a first opening and the second end of the body having a second opening; and 
 a cutting member within the body, the cutting member being bisected by an imaginary plane oriented perpendicular to the central axis of the body and the cutting member having a first cutting flute, a second cutting flute, a third cutting flute, and a fourth cutting flute, each of the first, second, third, and fourth cutting flutes extending inwardly from an interior surface of the body and comprising a first cutting blade, a second cutting blade, a third cutting blade, and a fourth cutting blade, respectively, with each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade having respective first and second shearing surfaces that are axially spaced apart along the central axis of the body, the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade establishing a first cutting socket and a second cutting socket, the first cutting socket being defined by the first shearing surfaces of the cutting blades and being accessible through the first opening of the body, and the second cutting socket being defined by the second shearing surfaces of the cutting blades and being accessible through the second opening of the body, the first cutting socket being constructed to cut the first weld face geometry into the weld face of the first welding electrode and the second cutting socket being constructed to cut the second weld face geometry into the weld face of the second welding electrode when the weld face of the first welding electrode is received in the first cutting socket and the weld face of the second welding electrode is received in the second cutting socket and the cutting tool is rotated about the central axis; 
 wherein the first, second, third, and fourth cutting blades are circumferentially spaced from each other such that each of the first, second, third, and fourth cutting blades is oriented transverse to each of its two circumferentially adjacent cutting blades; 
 wherein the respective first shearing surface of each of the first, second, third, and fourth cutting blades comprises, relative to the imaginary plane, a distal convex end portion and a proximal end portion extending inwardly from the distal convex end portion of the respective first shearing surface, the proximal end portion of the respective first shearing surface of each of the first, second, third, and fourth cutting blades having corresponding leading and trailing edges relative to rotation of the cutting tool about the central axis, wherein the proximal end portion of the respective first shearing surface of each of the first, second, third, and fourth cutting blades is inclined at a positive relief angle such that the corresponding leading edge of the respective first shearing surface of each of the first, second, third, and fourth cutting blades is more distal to the imaginary plane than is the corresponding trailing edge of the respective first shearing surface of each of the first, second, third, and fourth cutting blades; 
 wherein the respective second shearing surface of each of the first, second, third, and fourth cutting blades comprises, relative to the imaginary plane, a distal convex end portion and a proximal end portion extending inwardly from the distal convex end portion of the respective second shearing surface, the proximal end portion of the respective second shearing surface of each of the first, second, third, and fourth cutting blades having corresponding leading and trailing edges relative to rotation of the cutting tool about the central axis, wherein the proximal end portion of the respective second shearing surface of each of the first, second, third, and fourth cutting blades is inclined at a positive relief angle such that the corresponding leading edge of the respective second shearing surface of each of the first, second, third, and fourth cutting blades is more distal to the imaginary plane than is the corresponding trailing edge of the respective second shearing surface of each of the first, second, third, and fourth cutting blades. 
 
     
     
       2. The cutting tool set forth in  claim 1 , wherein each of the cutting flutes comprises a respective elongate foot, and wherein each elongate foot of the cutting flutes supports the cutting blade of its respective cutting flute at the interior surface of the body. 
     
     
       3. The cutting tool set forth in  claim 2 , wherein the interior surface of the body has retention channels that extend axially from the first end of the body to the second end of the body, each of the retention channels being defined by a respective depressed surface of the interior surface of the body, and wherein each elongate foot of the cutting flutes is separately friction fit within one of the retention channels to fixedly retain the cutting member within the body. 
     
     
       4. The cutting tool set forth in  claim 2 , wherein each elongate foot of the cutting flutes is integrally formed with the interior surface of the body to fixedly retain the cutting member within the body. 
     
     
       5. The cutting tool set forth in  claim 1 , wherein the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade are opposed from each other and separated circumferentially by the first shearing surface of the second cutting blade and the first shearing surface of the fourth cutting blade such that each of the first shearing surface of the second cutting blade and the first shearing surface of the fourth cutting blade is oriented transverse to the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade, each of the leading edge and the trailing edge of the proximal end portion of the first shearing surface of the first cutting blade and the leading edge and the trailing edge of the proximal end portion of the first shearing surface of the third cutting blade being profiled so as to extend outwardly from the central axis of the body to the distal convex end portion of the first shearing surface of the first cutting blade and the distal convex end portion of the first shearing surface of the third cutting blade, respectively, and wherein the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade are opposed from each other and separated circumferentially by the second shearing surface of the first cutting blade and the second shearing surface of the third cutting blade such that each of the second shearing surface of the first cutting blade and the second shearing surface of the third cutting blade is oriented transverse to the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade, each of the leading edge and the trailing edge of the proximal end portion of the second shearing surface of the second cutting blade and the leading edge and the trailing edge of the proximal end portion of the second shearing surface of the fourth cutting blade being profiled so as to extend outwardly from the central axis of the body to the distal convex end portion of the second shearing surface of the second cutting blade and the distal convex end portion of the second shearing surface of the fourth cutting blade, respectively. 
     
     
       6. The cutting tool set forth in  claim 1 , wherein the distal convex end portion of each of the first shearing surface of the first cutting blade, the first shearing surface of the second cutting blade, the first shearing surface of the third cutting blade, and the first shearing surface of the fourth cutting blade has corresponding leading and trailing edges relative to rotation of the cutting tool about the central axis, and wherein the distal convex end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is inclined at a positive relief angle such that the corresponding leading edge of the distal convex end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is more distal to the imaginary plane than is the corresponding trailing edge of the distal convex end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade. 
     
     
       7. The cutting tool set forth in  claim 1 , wherein the body comprises an annular wall having an exterior surface that includes an integral retaining nut, the integral retaining nut having a plurality of planar surfaces that are arranged around the exterior surface and intersect at circumferentially spaced axial edges. 
     
     
       8. The cutting tool set forth in  claim 7 , wherein the body further comprises an integral radial flange that adjoins and bears on an axial end of the integral retaining nut to provide a seating surface that projects transversely from each of the planar surfaces of the integral retaining nut. 
     
     
       9. The cutting tool set forth in  claim 1 , wherein the proximal end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the first weld face geometry that is cut into the weld face of the first welding electrode comprises a planar or domed base weld face surface that has a diameter between 3 mm and 16 mm, and wherein the proximal end portion of the respective second shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the second weld face geometry that is cut into the weld face of the second welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the second welding electrode along with a plurality of terraces that surround the central plateau. 
     
     
       10. The cutting tool set forth in  claim 1 , wherein the proximal end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the first weld face geometry that is cut into the weld face of the first welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the first welding electrode, and wherein the proximal end portion of the respective second shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the second weld face geometry that is cut into the weld face of the second welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and a series of upstanding circular ridges that project outwardly from the domed base weld face surface of the weld face of the second welding electrode. 
     
     
       11. The cutting tool set forth in  claim 10 , wherein the series of upstanding circular ridges includes anywhere from two to ten upstanding circular ridges that increase in diameter from an innermost upstanding circular ridge to an outermost upstanding circular ridge, the upstanding circular ridges being spaced apart on the domed base weld face surface of the weld face of the second welding electrode by a distance of 50 μm to 1800 μm, and each of the upstanding circular ridges having a ridge height that ranges from 20 μm to 500 μm. 
     
     
       12. The cutting tool set forth in  claim 1 , wherein the proximal end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the first weld face geometry that is cut into the weld face of the first welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the first welding electrode, and wherein the proximal end portion of the respective second shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the second weld face geometry that is cut into the weld face of the second welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the second welding electrode along with a plurality of terraces that surround the central plateau of the weld face of the second welding electrode. 
     
     
       13. The cutting tool set forth in  claim 1 , wherein the proximal end portion of the respective first shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the first weld face geometry that is cut into the weld face of the first welding electrode comprises a planar or domed base weld face surface that has a diameter between 3 mm and 16 mm, and wherein the proximal end portion of the respective second shearing surface of each of the first cutting blade, the second cutting blade, the third cutting blade, and the fourth cutting blade is profiled so that the second weld face geometry that is cut into the weld face of the second welding electrode comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the second welding electrode. 
     
     
       14. A cutting tool capable of dressing a weld face of a first welding electrode so that the weld face of the first welding electrode has a first weld face geometry, and dressing a weld face of a second welding electrode so that the weld face of the second welding electrode has a second weld face geometry, in which the first weld face geometry and the second weld face geometry are different from each other, the cutting tool comprising:
 a body that extends longitudinally along a central axis between a first end and a second end, and 
 a cutting member within the body, the cutting member establishing a first cutting socket accessible through a first opening at the first end of the body and a second cutting socket accessible through a second opening at the second end of the body, the cutting member comprising a first cutting flute that includes a first cutting blade having first and second shearing surfaces that are axially spaced apart along the central axis of the body and that define, at least in part, the first and second cutting sockets, respectively, wherein an imaginary plane oriented perpendicular to the central axis bisects the cutting member, wherein the first shearing surface of the first cutting blade comprises a distal convex end portion and a proximal end portion relative to the imaginary plane, the proximal end portion of the first shearing surface of the first cutting blade extending radially inward from the distal convex end portion of the first shearing surface and being profiled to cut the first weld face geometry into the weld face of the first welding electrode, and wherein the second shearing surface of the first cutting blade comprises a distal convex end portion and a proximal end portion relative to the imaginary plane, the proximal end portion of the second shearing surface of the first cutting blade extending radially inward from the distal convex end portion of the second shearing surface and being profiled to cut the second weld face geometry into the weld face of the second welding electrode; 
 wherein the proximal end portion of the first shearing surface of the first cutting blade is profiled so that the first weld face geometry that is cut into the weld face of the first welding electrode by the proximal end portion of the first shearing surface of the first cutting blade comprises a planar or domed base weld face surface that has a diameter between 3 mm and 16 mm, and wherein the proximal end portion of the second shearing surface of the first cutting blade is profiled so that the second weld face geometry that is cut into the weld face of the second welding electrode by the proximal end portion of the second shearing surface of the first cutting blade comprises a domed base weld face surface that has a diameter between 8 mm and 20 mm and further includes a central plateau centered on the domed base weld face surface of the weld face of the second welding electrode. 
 
     
     
       15. The cutting tool set forth in  claim 14 , wherein the cutting member further comprises a second cutting flute having a second cutting blade, a third cutting flute having a third cutting blade, and a fourth cutting flute having a fourth cutting blade, the first, second, third, and fourth cutting blades being circumferentially spaced from each other such that each of the first, second, third, and fourth cutting blades is oriented transverse to each of its two circumferentially adjacent cutting blades;
 wherein each of the second cutting blade, the third cutting blade, and the fourth cutting blade includes respective first and second shearing surfaces that are axially spaced apart along the central axis of the body; 
 wherein the respective first shearing surface of each of the second cutting blade, the third cutting blade, and the fourth cutting blade comprises a distal convex end portion and a proximal end portion relative to the imaginary plane, the proximal end portion of each of the first shearing surface of the second cutting blade, the first shearing surface of the third cutting blade, and the first shearing surface of the fourth cutting blade extending radially inwardly from the distal convex end portion of the first shearing surface of the second cutting blade, the distal convex end portion of first shearing surface of the third cutting blade, and the distal convex end portion of first shearing surface of the fourth cutting blade, respectively, wherein the first shearing surface of the second cutting blade, the first shearing surface of the third cutting blade, and the first shearing surface of the fourth cutting blade define the first cutting socket along with the first shearing surface of the first cutting blade; 
 wherein the respective second shearing surface of each of the second cutting blade, the third cutting blade, and the fourth cutting blade comprises a distal convex end portion and a proximal end portion relative to the imaginary plane, the proximal end portion of each of the second shearing surface of the second cutting blade, the second shearing surface of the third cutting blade, and the second shearing surface of the fourth cutting blade extending radially inwardly from the distal convex end portion of the second shearing surface of the second cutting blade, the distal convex end portion of second shearing surface of the third cutting blade, and the distal convex end portion of second shearing surface of the fourth cutting blade, respectively, wherein the second shearing surface of the second cutting blade, the second shearing surface of the third cutting blade, and the second shearing surface of the fourth cutting blade define the second cutting socket along with the second shearing surface of the first cutting blade. 
 
     
     
       16. The cutting tool set forth in  claim 15 , wherein the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade are opposed from each other and separated circumferentially by the first shearing surface of the second cutting blade and the first shearing surface of the fourth cutting blade such that each of the first shearing surface of the second cutting blade and the first shearing surface of the fourth cutting blade is oriented transverse to the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade;
 each of the proximal end portion of the first shearing surface of the first cutting blade and the proximal end portion of the first shearing surface of the third cutting blade having corresponding leading and trailing edges relative to rotation of the cutting tool about the central axis, the proximal end portion of each of the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade being inclined relative to the imaginary plane from the corresponding leading edge to the corresponding trailing edge and, further, the leading edge and the trailing edge of the proximal end portion of each of the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade being profiled so as to extend outwardly as the corresponding leading and trailing edges of the proximal end portion of each of the first shearing surface of the first cutting blade and the first shearing surface of the third cutting blade progress towards the distal convex end portion of the first shearing surface of the first cutting blade and the distal convex end portion of the first shearing surface of the third cutting blade, respectively; 
 wherein the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade are opposed from each other and separated circumferentially by the second shearing surface of the first cutting blade and the second shearing surface of the third cutting blade such that each of the second shearing surface of the first cutting blade and the second shearing surface of the third cutting blade is oriented transverse to the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade; 
 each of the proximal end portion of the second shearing surface of the second cutting blade and the proximal end portion of the second shearing surface of the fourth cutting blade having corresponding leading and trailing edges relative to rotation of the cutting tool about the central axis, the proximal end portion of each of the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade being inclined relative to the imaginary plane from the corresponding leading edge to the corresponding trailing edge and, further, the leading edge and the trailing edge of the proximal end portion of each of the second shearing surface of the second cutting blade and the second shearing surface of the fourth cutting blade being profiled so as to extend outwardly as the corresponding leading and trailing edges of the proximal end portion of each of the second shearing surface second cutting blade and the second shearing surface of the fourth cutting blade progress towards the distal convex end portion of the second shearing surface of the second cutting blade and the distal convex end portion of the second shearing surface of the fourth cutting blade, respectively. 
 
     
     
       17. A cutting tool comprising:
 a body that extends longitudinally along a central axis between a first end and a second end, and 
 a cutting member within the body, the cutting member being bisected by an imaginary plane oriented perpendicular to the central axis and further establishing (i) a first cutting socket accessible through a first opening at the first end of the body and (ii) a second cutting socket accessible through a second opening at the second end of the body, the cutting member comprising a first cutting flute, a second cutting flute, a third cutting flute, and a fourth cutting flute that are circumferentially spaced from each other within the body of the cutting tool, each of the first cutting flute, the second cutting flute, the third cutting flute, and the fourth cutting flute comprising:
 a respective cutting blade; and 
 a respective elongate foot that supports the corresponding cutting blade at an interior surface of the body, wherein the interior surface of the body has retention channels that extend axially from the first end of the body to the second end of the body, each of the retention channels being defined by a depressed surface of the interior surface of the body, and wherein the elongate foot of each of the first cutting flute, the second cutting flute, the third cutting flute, and the fourth cutting flute is separately friction fit within one of the retention channels to fixedly retain the cutting member within the body; 
 wherein each of the cutting blades includes respective first and second shearing surfaces that are axially spaced apart along the central axis of the body and that define, at least in part, the first and second cutting sockets, respectively, wherein each of the first shearing surfaces comprises a respective distal convex end portion and a respective proximal end portion relative to the imaginary plane, each of the distal convex end portions of the first shearing surfaces extending radially inward from the respective elongate foot proximate the first end of the body, and each of the proximal end portions of the first shearing surfaces extending radially inward from the respective distal convex end portion of the respective first shearing surface and away from a plane of the first opening of the body, and wherein each of the second shearing surfaces comprises a respective distal convex end portion and a respective proximal end portion relative to the imaginary plane, each of the distal convex end portions of the second shearing surfaces extending radially inward from the respective elongate foot proximate the second end of the body, and each of the proximal end portions of the second shearing surfaces extending radially inward from the respective distal convex end portion of the respective second shearing surface and away from a plane of the second opening of the body; 
 wherein the proximal end portion of the first shearing surface of the cutting blade of each of the first cutting flute, the second cutting flute, the third cutting flute, and the fourth cutting flute is profiled to achieve by cutting, upon rotation of the cutting tool about the central axis of the body, a first weld face geometry; 
 wherein the proximal end portion of the second shearing surface of the cutting blade of each of the first cutting flute, the second cutting flute, the third cutting flute, and the fourth cutting flute is profiled to achieve by cutting, upon rotation of the cutting tool about the central axis of the body, a second weld face geometry.